In the preparation of artwork for printing, particularly in the production of colour separations for magazines, posters and other media from originals such as transparencies or prints, it is normally required to modify the original both in its scale, by enlargement or reduction, and to select the area of the original to bee reproduced, by cropping. It may also be necessary to modify the angular disposition of the subject relative to the boundaries of the original, either to correct for errors or to produce an artificial image. In the prior art, these measurements and calculations have been carried out manually, with consequent inaccuracy and cost.
An object of the present invention is to provide devices which facilitate the use of a digital computer in such operations, by linking the movement of a cursor or the like over the original, with a computer providing real-time calculation of the scaling required, and automatic recordal of the scaling parameters.